Anticoagulant protein C pathway defective in majority of thrombophilic patients [see comments]

A defect involving poor anticoagulant response to activated protein C (APC), an anticoagulant serine protease known to inactivate factors Va and VIIIa in plasma, was recently reported and the existence of a novel APC cofactor was suggested. To define the frequency of this defect among 25 venous thrombophilic patients with no identifiable laboratory test abnormality and among 22 patients previously identified with heterozygous protein C or protein S deficiency, the APC-induced prolongation of the activated partial thromboplastin time assay for these patients was compared with results for 35 normal subjects. The results show that this new defect in anticoagulant response to APC is surprisingly present in 52% to 64% of the 25 patients, ie, in the majority of previously undiagnosed thrombophilia cases, but is not present in 20 of 22 heterozygous protein C or protein S deficient patients, suggesting that the new factor is a risk factor independent of protein C or protein S deficiency. The results demonstrate that abnormalities in the anticoagulant protein C pathway are present in the majority of thrombophilic patients.     

Tranexamic acid, an inhibitor of plasminogen activation, reduces urinary collagen cross-link excretion in both experimental and rheumatoid arthritis

The plasminogen activation system is one of the enzyme systems held responsible for bone and cartilage degradation in rheumatoid arthritis (RA). In this study, we evaluated the effect of tranexamic acid (TEA), an inhibitor of plasminogen activation, on urinary collagen cross-link excretion and radiological joint damage in rat adjuvant arthritis (AA) and on urinary collagen cross-link excretion in patients with RA. In the animal study, adjuvant arthritis was induced in male Lewis rats. From day 7 onward, high-dose TEA (500 mg/kg body weight, once daily) or placebo was administered orally. Study groups consisted of TEA-treated normal rats (C + TEA), placebo-treated normal rats (C + plac), AA rats treated with TEA (AA + TEA) or with placebo (AA + plac). To monitor joint destruction, urinary collagen cross-link excretion (pyridinoline, HP; deoxypyridinoline, LP) was measured by high-performance liquid chromatography at days 14 and 21. Radiological evaluation of joints was performed at day 21. In the patient study, TEA was administered to nine patients with RA as adjuvant medication (approximately 20 mg/kg body weight, three times daily) for 12 weeks. Urinary HP and LP excretion levels were measured before and during TEA treatment, and 4 weeks after the cessation of TEA treatment. In AA + TEA rats, a significant reduction of HP and a tendency towards a reduction of LP excretion were found compared with AA + plac rats (P < 0.05), at day 14, whereas the HP/LP ratio did not change. No difference was observed in HP, LP excretion, HP/LP ratio and radiological damage score between the TEA- and placebo-treated AA rats at day 21. In RA patients, a significant reduction of HP and LP excretion was found during the TEA treatment period (P < 0.05). After the cessation of TEA treatment, HP and LP excretion increased towards baseline levels. No effect on disease activity was observed. The plasmin antagonist TEA reduced the excretion of collagen pyridinoline cross-links in both experimental and rheumatoid arthritis. As such, this study not only supports the involvement of the plasminogen activation system in the destructive phase of arthritis, but also suggests a beneficial effect of therapeutic strategies directed against inhibition of matrix proteolysis.      

Monoclonal antibody T101 in T cell malignancies: a clinical, pharmacokinetic, and immunologic correlation

Eight patients with cutaneous T cell lymphomas (CTCL) and five with various other T cell malignancies were treated with mouse monoclonal antibody (MoAb) T101. Doses of 1 to 500 mg were administered weekly over a two-hour period and resulted in one complete remission (convoluted T cell lymphoma) and one partial remission (CTCL). Remission duration was 6 weeks and 3 months, respectively. Frequent toxicities were pruritus, hives, flushing, and shortness of breath. Supraventricular arrhythmias and blood pressure instability were also observed. Complete targeting of peripheral blood T cells was achieved with 1 mg of MoAb in the nonleukemic patients (WBC less than 10,000/microL), and free, bioavailable antibody was present at the next (10-mg) dose level. Even higher doses resulted in substantial antibody excess that persisted for as long as 6 weeks. Serum concentrations of MoAb decreased with increasing number of peripheral blood T cells, and 25 to 35 mg of T101 were required for induction of antibody excess in leukemic patients. Excess antibody induced antigenic modulation, which was of consequence only if MoAb excess persisted to the next treatment. In the original treatment, the rapidly administered MoAb was able to target and remove peripheral blood T cells before the development of antigenic modulation. Antimouse antibodies developed in three patients. Their presence rendered further therapy ineffective and was associated with an anaphylactic reaction in one patient. Development of these antibodies could not be predicted by lymphoproliferative assays. In these assays, however, the T101 protein strongly stimulated the mononuclear cells of the patient who reached the only complete remission of this trial. Immunologic stimulation by the MoAb thus might have played a role in this patient's antitumor response. In summary, therapy with MoAb T101 was specific but only modestly efficacious. Rapid infusion of nonmodulating doses of antibody provided excellent targeting and removal of peripheral blood T cells and might be a valid approach in future trials with immunoconjugated T101.     

Priming of human neutrophils with N-formyl-methionyl-leucyl- phenylalanine by a calcium-independent, pertussis toxin-insensitive pathway

Resting neutrophils may be "primed" to augmented effector function, eg, superoxide (O2-) production in the respiratory burst, upon a second stimulation with a variety of soluble agonists including formylated methionyl-leucyl-phenylalanine (FMLP) and phorbol myristate acetate (PMA). At priming concentrations of FMLP (5 x 10(-9) mol/L) that did not initiate O2- generation, two metabolic activities were noted: (1) approximately a threefold increase in the baseline intracellular calcium (Ca++i) level, that was not dependent on extracellular Ca++, and (2) a rapid rise in intracellular pH that was blocked by 5-(N,N- dimethyl) amiloride (DA), that had no effect on the Ca++i response to priming. Furthermore, there were no significant increases in inositol metabolites in cells primed and stimulated with FMLP compared with cells receiving the stimulating dose of FMLP alone and pretreatment with pertussis toxin (PT) (before the addition of the priming -5 x 10(- 9) mol/L dose of FMLP), whereas abolishing the response to FMLP during the second stage of stimulation, had (1) no effect on FMLP-primed cells subsequently stimulated with PMA, and (2) only partially ablated the rise in Ca++i initiated with FMLP. That FMLP priming involved distinctive processes to those of the well characterized FMLP-coupled Ca++-dependent activation cascade was shown by the full priming effect attained in a Ca++-free buffer, which did not sustain an O2- response to a second-stage FMLP stimulation, but sustained a primed response to PMA. These data demonstrate that FMLP primes human neutrophils by a Ca++-independent and PT-insensitive pathway, offering a functional model for studying heterogeneous FMLP receptor-coupled reactions.     

Extramammary Paget’s disease in Korea: its association with gastrointestinal neoplasms

Background  Extramammary Paget’s disease (EMPD) most commonly occurs in the perineal and genital areas of elderly people. The current treatment of choice is adequate surgical excision. Materials and methods  Between 1990 and 2007, 28 patients (27 men and one woman) with EMPD were treated at Asan Medical Center, Seoul, Korea, by wide local excision (WLE) with a 2- to 3-cm normal skin margin. “Carcinoma in situ” (CIS) was defined as confinement of Paget cells to the epithelium, whereas “invasive carcinoma” was defined as infiltration of Paget cells into more than dermal connective tissue. Results  Of the 28 lesions, 21 (75%) were located in the penoscrotal area. Six (21.4%) patients had associated gastrointestinal neoplasms, three with associated gastrointestinal malignancies and four with synchronous colorectal adenomas, including one with both. Surgical procedures included WLE with primary repair in 13 patients (46.4%), WLE with skin graft in 12 (42.9%), WLE with skin graft and Gracilis muscle transposition in two (7.1%), and combined abdominoperineal resection and distal gastrectomy in one (3.6%). Four patients (14.3%) also underwent inguinal lymph node dissection, with three found to have lymph node metastases. Of 11 patients with invasive carcinoma, three (27.3%) had lymph node metastases, compared with none of 17 patients with CIS. Patients with lymph node metastases showed a significantly lower disease-specific survival rate (P = 0.008). Patients with invasive carcinoma tended to have a lower disease-specific survival rate (P = 0.087). Conclusions  EMPD in Korea showed an absolute male predominance and an association with gastrointestinal neoplasms. Lymph node metastasis significantly affected, and depth of invasion tended to affect, disease-specific survival rate. This study was supported by a grant of the Korea Health 21 R&D Project, Ministry & Welfare, Republic of Korea (A062254).     

Clonal identification of Burkitt's Lymphoma Arising from Lymphocyte-Predominant Hodgkin's Disease

The occurrence of large cell lymphomas subsequent to, or concurrent with, lymphocyte predominant Hodgkin's disease (LPHD) is a well-documented phenomenon. We present a case of Burkitt's lymphoma of the bladder, occurring after the successful treatment of LPHD of a cervical lymph node. To evaluate the clonal relationship of the two tumours, we amplified the complementarity-determining-region 3 of two samples from paraffin-embedded slides, using the polymerase chain reaction (PCR). The sequences of the PCR products showed 96% homology to each other. These results indicate that the malignant clone of Burkitt's lymphoma arose from the corresponding LPHD.     

Interleukin 1 induces human marrow stromal cells in long-term culture to produce granulocyte colony-stimulating factor and macrophage colony- stimulating factor

Pure interleukin 1 (IL 1) was found to stimulate established human bone marrow stromal layers in long-term culture to produce colony- stimulating activity (CSA). Maximal concentrations in the culture medium were reached 24 hours after a single IL 1 pulse. The effect could be neutralized by a specific rabbit anti-IL 1 antiserum. Stromal layers, once stimulated by IL 1, continued to release CSA into the culture medium in the absence of exogenous IL 1. A second IL 1 pulse induced CSA release in an identical manner, as did the primary stimulation, indicating that the CSA released was actively produced. Using specific immunologic assays, both granulocyte colony-stimulating factor (G-CSF) and macrophage CSF (M-CSF) could be identified in the culture supernatants, and production of both factors was inducible by IL 1. Shortly after initiation of the long-term marrow cultures "spontaneous" G-CSF and M-CSF release occurred. The release of G-CSF diminished following addition of the anti-IL 1 antiserum, indicating that endogenous production of IL 1 by stromal cells had contributed to this effect. These results further support the role of IL 1 as an important modulator of CSF production by cells of the hematopoietic microenvironment.     

Nodular mixed lymphoma: results of a randomized trial failing to confirm prolonged disease-free survival with COPP chemotherapy

Fifty-two patients with stage III or IV nodular mixed lymphocytic- histiocytic lymphoma (NM) were entered on a prospective randomized trial comparing cyclophosphamide-prednisone (CP) to either COPP (cyclophosphamide, vincristine, procarbazine, prednisone) or BCVP (BCNU, cyclophosphamide, vincristine, prednisone). The COPP regimen utilized in this Eastern Cooperative Oncology Group (ECOG) trial was similar to the four-drug regimen C-MOPP reported by the National Cancer Institute to achieve prolonged relapse-free survival in this histology. No significant differences in complete response rates, response duration, or overall survival were noted among the three regimens. A pattern of continuous late relapse was observed for all three chemotherapy programs. Although 11 of the 18 (61%) COPP patients achieved a complete response, only 3/11 (27%) remain disease-free with a median follow-up of over 3 yr. However, two of these three long-term complete responders have died with no clinical evidence of recurrent disease. The COPP patients received 84% of the calculated ideal doses of cyclophosphamide and 78% of the ideal dosage of procarbazine. Grade 3-4 hematologic toxicity was noted in 22% of the COPP group, 36% with BCVP, and 0% for the CP patients. We were unable to confirm the ability of COPP to achieve durable complete remissions in NM lymphoma. The cyclophosphamide-prednisone combination was equally effective when compared with COPP and BCVP, but produced minimal toxicity.     

Pancreatic microcirculation of dogs measured by hydrogen gas generated by electrolysis

Electrochemically generated hydrogen gas was used to measure pancreatic regional blood flow in dogs by Koshu's method. This method is not necessary to inhale H2 gas and it is possible to generate H2 gas from H3O- in tissue in precise areas and to measure pancreatic regional blood flow easily, immediately, and steadily. Reliability and reproducibility were as good as for the H2 gas clearance method. Although the H2 gas clearance method has disadvantages in measuring pancreatic regional blood flow, especially in hypocirculation and in small animals, this new method can be used effectively. It will be useful in the investigation and examination of pathologic conditions in small animals and in humans.     

Antiphospholipid syndrome in Asians: clinical manifestations,serological markers and outcome of the National University of Singapore/National University Hospital antiphospholipid cohort

Background: There is a paucity of studies on antiphospholipid syndrome (APS) in Asian patients. Aim: This is the first study in Singapore to describe the clinical features, serological markers and outcomes of one of the largest cohort of APS patients in South‐east Asia. Method: One hundred and forty‐six patients were studied. Results: Within the study group, 89 were primary APS and 57 secondary APS. Age range: 16–84 years (mean Age: 50.1 years). Male : female ratio: 1 : 2.1. Racial distribution: Chinese, 69.2%; Malays, 18.5%; Indians, 11.7%. Systemic lupus erythematosus was the commonest disease associated in 48 patients (32.9%), while 17 (11.6%) had lupus‐like disease. Eighty‐two (56.2%) patients had arterial thrombosis, 37 (25.3%) patients had venous thrombosis, 14 (9.6%) had arterial and venous thrombosis while 17 (11.6%) had obstetric manifestations; 28.8% had thrombocytopenia. Clinical manifestations were diverse with neurological (49.3%), cardiac (40%), renal (23.6%) involvement. There were also several unusual presentations. Recurrent thrombosis occurred in 24.6%. Two had catastrophic APS and there were 12 deaths (9.6%). Antiphospholipid antibody testing included lupus anticoagulant, serum aCL IgG, IgM and IgA, anti‐β2 glycoprotein I (aβ2‐GPI) IgG, IgM, and IgA. The serological positivity rates of the various antiphospholipid antibodies were reported. aβ2‐GPI was positive in 67% of those tested, of which aβ2‐GPI IgA was the most common subtype. The presence of the aβ2‐GPI was associated with recurrent venous thrombosis. Conclusion: The clinical manifestations of APS in Asian patients were diverse and multisystemic. Recurrent thrombosis rate was high with significant morbidity and mortality.